Concrete decks typically include a series of concrete sections or slabs separated by expansion joints. The expansion joints allow the adjacent deck sections to move a small amount with respect to each other to reduce cracking caused by settling, thermal expansion, vibration, load flex, wind load and other types of movement. Nevertheless, normal wear and tear including heavy loads, freeze-thaw cycles and other stresses expose the deck sections to spalling concrete loss at the expansion joints, eventually creating potholes. Occasional maintenance is therefore required to repair and stop the progression of the damage.
Repairing concrete damage at an expansion joint is complicated because simply filling the expansion joint as part of the repair is inadvisable. This is because filling the expansion joint with concrete repair material effectively defeats the purpose of the expansion joint, causing the repair material to crack and spall quickly due to relative movement of the adjacent slabs. Conventional approaches to preserving the expansion joint while repairing the damage typically involves a two-stage repair technique that requires closing the road for an extended period, which can lead to detours and extreme congestion. For example, the prevailing concrete deck repair technique uses forms temporarily placed along each slab of the expansion joint, which are backfilled with concrete repair material. The forms are then removed with the aid of a bond breaker and the patch is allowed to cure overnight. The road crew returns the next day (weather permitting) to clean the bond breaker from the repaired surfaces and install a neoprene, silicone rubber, or silicone rubber caulk seal into the expansion joint to prevent water, sand and other debris from infiltrating the joint. The repair process requires closing the roadway for at least two times, which can be extremely disruptive to the traffic. In some cases, the road crew may have to repair each side of expansion joint on separate days, which further extends the repair process.
At present, conventional concrete repair techniques do not allow a damaged expansion joint to be repaired and sealed in a single repair session. There is, therefore, a need for improved techniques for repairing and sealing concrete damage at expansion joints.